Au Sable River Fishing Guide

The stretch anglers mean when they say "the Au Sable" is the mainstream's Holy Waters: roughly 8.7 miles from Burton's Landing down to Wakeley Bridge, just east of Grayling. It is flies-only and catch-and-release, and it has been a proving ground for fly fishing for a century. Trout Unlimited was founded on this river in 1959, and the town of Grayling takes its name from the Arctic grayling that once filled it.

It is a spring-fed river: cold, clear, and remarkably stable, with a gravel bottom, sweeping cedar banks, and logjams that hold fish. Brown trout dominate, with wild brook trout in the mix and the occasional rainbow. The North Branch, the South Branch (with its no-kill Mason Tract), and the mainstream each fish a little differently, but all reward a quiet approach and a good drift.

The Au Sable is a dry-fly river, and the calendar matters more than almost anything. The marquee event is the Hex (Hexagenia limbata), a giant mayfly that hatches after dark in late June and brings the biggest browns up to feed. Around it, a full season of hatches keeps fish looking up.

In summer's low, clear water, fish the edges of the day: an hour after first light and the last hour before dark. Downsize to 5x or 6x, and when nothing is rising in the afternoon, an ant or a beetle tight to the bank often is.

Public landings and bridges give access to the mainstream and the branches. From upstream to down:

Wade quietly on the gravel, watch for sweepers and soft bottom near the banks, and give floating anglers a clear line through.

The Au Sable is not one rulebook. The famous water is gear-restricted, but much of the system fishes under Michigan's general trout-stream rules, where bait and spinning lures are perfectly legal. Knowing which reach you are standing in is the whole game. A Michigan fishing license is required everywhere.

In short: if you want to fish live bait or spinning lures, stay on the general-regulation water, the mainstream above Burton's Landing or below Wakeley Bridge, and the tributaries outside the marked flies-only reaches. The Holy Water and the Mason Tract are flies-only and no-kill; the Mio Trophy Water takes flies and lures but no bait. Barbless or pinched-barb hooks make release easy and are the norm on the fly water.

Gear that fits the river: an 8.5 to 9 foot rod in 4 to 6 weight, a 9 foot leader tapered to 4x to 6x, and waders (the water stays cold even in July). For the Hex, night mousing, or throwing streamers, step up to a 6 weight and 2x to 3x.

Etiquette keeps this river what it is: don't crowd or step in below an angler who is working a rising fish, give the riverboats room, pack out everything you bring, respect the private frontage, and keep the evening Hex water quiet. Newcomers who fish considerately are always welcome.

The Holy Water and the Mason Tract are flies-only, but the general-regulation mainstream (above Burton's Landing and below Wakeley Bridge) and the Mio Trophy Water are open to artificial lures. On the Trophy Water, pinch the barbs and use a single-point hook, swap the trebles on a plug for a single siwash. Then match the lure to the season, the water, and the light.

Two dials do most of the work. Light: the lower the light, at dawn, at dusk, or under heavy cloud, the larger and darker the lure and the more flash or vibration it can carry; bright midday calls for small, natural, and silver. Water: high or stained flows reward gold, chartreuse, black, and thump; low, clear water rewards silver, natural colors, and a quiet approach on lighter line. Where you can keep a trout, mind the DNR size and daily limits in Section 5.

Three trout share the river. Wild brook trout are the natives, brown trout grow the biggest, and rainbows round out the mix. Handle every fish wet-handed and release it quickly. Here is how to tell them apart at a glance.